The invention relates to a solar panel for space satellites, having a plane surface comprising a plurality of photovoltaic cells disposed side by side and substantially forming a grid, said cells being electrically connected into at least one serpentine, each serpentine comprising cells connected in series two by two forming parallel cell segments, two successive segments of a serpentine being electrically connected at their ends, and each serpentine comprising positive terminals and negative terminals.
The invention applies more particularly to the field of plane photovoltaic panels equipping satellites encountering a severe electrostatic environment, such as geosynchronous satellites, in which the photovoltaic cells are mounted on a substrate, for example. In a panel of this kind disclosed in the patent EP 0 938 141, the cells are connected to form U-shaped serpentines. Each serpentine has positive and negative terminals at its ends situated at an edge of the panel and the current produced by the serpentine is conveyed in the direction of the satellite by electrical cables. In these prior art panels, the positive and negative terminals that are contiguous have a high potential difference and carry a high current. The existence of these terminals a small distance apart and having a high potential difference encourages continuous electrical arcing between the terminals or between cells close to the terminals. This electrical arcing causes pyrolysis of the substrate and leads to irreversible short circuiting of the section consisting of the cells connected between the two short circuit points. More generally, arcing can occur between two adjacent cells of the panel which have a high potential difference. This phenomenon occurs as a consequence of the occurrence of a primary arc that is formed as a result of electrostatic charging of the insulative panel surface (cover glass), the primary arc being sufficient to strike a continuous arc.
The patent EP 0 938 141 discloses placing an insulative material between adjacent cells to block the path between cells, referred to as the gap, to the primary arcs. Secondly, to reduce the consequences of a short circuit, diodes are associated with the photovoltaic cells to reduce the short circuit current to the current supplied by only one section of cells. These two methods are not entirely satisfactory in that they tend in particular to add to the weight of the panel, which penalizes the electrical power/mass ratio. Secondly, these two methods require made-to-measure cells, which increases the fabrication cost of this kind of panel.